[rules-users] MVEL interpretation

My team is using Drools on a government project. As is usually the case with government projects, the security folks have their hands in every aspect of the project. They have big questions on MVEL, but I'm going to try to boil them down to one simple question: At what stage(s) of Drools's lifecycle does MVEL interpretation occur? I think that the compilation engine interprets the MVEL at compile time and converts it to generated Java code, though I don't know enough about the internals of the engine to say for sure. Stated another way, does Drools interpret rules written using the MVEL dialect at runtime? Thanks Mike